1. Field of the Invention
The present invention relates to a sheet handling machine used for, for example an automated teller machine (ATM), and more particularly, it relates to a sheet handling machine suitable for the handling of various bills different in size and thickness all over the world.
2. Description of the Related Art
An ATM is generally constructed in such a manner that bills to be deposited are directly inserted into the deposit port of the ATM, the inserted bills are automatically checked and counted by the bill handling machine of the ATM, the results thereof are displayed in real time, an approval (validation) of the display is entered by a user, and then deposit work for each handling is finished. Such a bill handling machine was constructed and adjusted specifically for bills of each country, because it was only necessary to handle the bills of Japan, Korea or the like, in which it was installed. Especially, sheet thickness checking means for checking the overlapped conveying of bills or the presence of foreign objects on a sheet surface needed to check only the thickness of one kind, as the thickness of a bill distributed in each country, Japan, Korea or the like, is constant irrespective of the kind of a bill.
As such conventional sheet thickness checking means for checking the thickness of one kind, there is, for example xe2x80x9cOVERLAPPED SHEET FEEDING DETECTORxe2x80x9d disclosed in JP-A-5-278901. The overlapped sheet feeding detector disclosed therein comprises: a reference roller as a reference for thickness measurement; a detecting roller brought into contact with the reference roller to be displaced; converting means for converting the displacement of the detecting roller into an electric signal; correcting means for correcting an error intrinsic to the reference roller based on the integrated value of the outputs of the converting means. Thus, detecting accuracy is prevented from being affected by the machining accuracy of the reference roller.
However, in new bills issued in recent years, various novel feature technologies are used for forgery prevention. Many of those features affect the thickness of a bill, the feature technologies are used in a part of the bill surface, and plural kinds of feature technologies are often used for one bill. For the conventional bill, a thickness was substantially constant over a full surface. In the case of the bills of recent years, however, a part of the bill using the feature technologies like those described above is different in thickness from the other parts, consequently causing a partial difference in thickness on the same bill surface. For example, a relatively frequently used security thread is prepared by stitching a thin and narrow tape made of metal or a resin in the manufacturing process of paper of a bill. A part of the security thread is generally thicker than the other parts of the bill surface.
To detect the tape thinner than the thickness of the bill, stuck to the bill surface, it is necessary to detect a change in thickness much smaller than that when the overlapping of bills is detected. However, since it is often the case that the thickness increase of a part of the security thread is substantially equal to the tape thickness, it is impossible to detect the tape of the bill having the security thread. Alternatively, tape detection was impossible only in the vicinity of the security thread.
The conventional technology of the bill handling machine is based on the assumption that a normal bill has a thickness constant on the full surface. No consideration was given to measures for dealing with a bill using novel feature technologies for forgery prevention like those described above.
For directly handling the bill by the bill handling machine, it is necessary to verify that the number of bills to be handled is one. A most reliable method for verifying that the number of bills is one is to check the thickness of the bill, and determine whether the thickness of the bill is equal to the amount of one sheet or more.
However, in the countries all over the world, a thickness was different from one bill to another depending on the kind of a bill even in one country, bills of a plurality of countries were inserted, and so on, varying the thickness of the bill. Consequently, it was impossible to handle the bills by the conventional bill handling machine. In addition, regulations have been gradually softened in Japan or Korea, resulting in the need to simultaneously handle domestic and overseas bills. Also in this case, it was impossible to handle those different in thickness from the domestic bills by the conventional bill handling machine.
The present invention was made to solve the foregoing problems, and it is an object of the invention to provide a bill handling machine for realizing an ATM, capable of surely verifying whether the number of bills is one or not even when bills varied in thickness depending on the kind of a bill are inserted, and a bill different in thickness is mixed in.
It is another object of the invention to provide a bill handling machine for realizing an ATM, capable of dealing with new bills using various novel feature technologies for forgery prevention, issued in recent years.
It is yet another object of the invention to provide a sheet handling machine capable of detecting a foreign object, e.g., a tape or the like, on a bill surface, even when a bill different in thickness is mixed in.
In order to achieve the foregoing object, in accordance with the invention, there is provided a sheet handling machine, comprising at least: sheet checking means for checking a sheet to specified its kind; sheet thickness checking means for checking the thickness of a sheet; and a control unit for controlling the above components. The sheet checking means measures a sheet fed in by various sensors, the result of the measurement is processed at the control unit, and the issuing country, the kind, and so on, of the sheet are specified. After the kind of the sheet has been specified, the control unit refers to the table of a relation between the kind of a sheet and thickness information held beforehand, and reads the reference thickness information of the sheet from the table. Then, a one-sheet determination unit of the control unit compares the information of a thickness actually measured by the sheet thickness checking means with the reference thickness information read from the table, determines that the number of sheets is one, and no foreign objects are present in a sheet surface if a relation therebetween is within a predetermined range, and that the number of sheet is other than one, and a foreign object is present in the sheet surface if the relation is outside the predetermined range.
According to the invention, a plurality of sheet thickness checking means are provided in a direction orthogonal to a sheet conveying direction, thickness information for a plurality of places of a sheet surface in a direction orthogonal to the conveying direction is fetched, and information regarding a portion partially different in thickness due to the use of a feature technology for forgery prevention is also written beforehand. By comparing the information of a thickness actually measured at the plurality of places of a bill surface with the reference thickness information of the full bill surface, it is possible to deal with a bill using a novel feature technology for forgery prevention.